Today, the agency decided that “the available scientific evidence did not meet the criteria to classify glyphosate as a carcinogen, as a mutagen or as toxic for reproduction”.

“This conclusion was based both on the human evidence and the weight of the evidence of all the animal studies reviewed,” Tim Bowmer, the chairman of Echa’s Committee for Risk Assessment, said in an online briefing.

A classification that glyphosate causes serious eye damage and is toxic to aquatic life will remain in place. The controversy over its health and environmental effects though, looks set to rumble on.

The new Echa opinion now faces an internal check before it is submitted to the European commission which will restart EU discussions so that a final decision can be reached by the end of the year.

Greenpeace EU’s food policy director, Franziska Achterberg, said: “Echa has gone to great lengths to sweep all evidence that glyphosate can cause cancer under the carpet. The data vastly exceeds what’s legally necessary for the EU to ban glyphosate, but Echa has looked the other way.”

Industry groups heartily welcomed the assessment. “Science prevailed,” said Graeme Taylor, of the European Crop Protection Agency. “Glyphosate is not carcinogenic. We expect the European commission to move swiftly with the registration process for the substance in the EU and grant a 15-year approval.”

These suggested that the US agriculture giant was given a heads up by Jess Rowland, an EPA deputy division director, about an International Agency for Research on Cancer report linking glyphosate to cancer, allowing it to mount a pre-publication PR offensive. Rowland also allegedly told a Monsanto executive that he would try to prevent a separate government probe of glyphosate, saying: “If I can kill this, I should get a medal.”

In a statement in the New York Times, Monsanto said: “Glyphosate is not a carcinogen.” Monsanto also rebutted criticisms concerning the academic research it underwrites.

Other documents revealed in the US suit include an extraordinary letter from Marion Copley, an award-winning EPA scientist, who said it was “essentially certain” that glyphosate caused cancer.

Copley, who was herself dying of cancer, made several conflicts of interests allegations.

“I have cancer and I don’t want these serious issues in HED [health effects division] to go unaddressed before I go to my grave,” she wrote in her valedictory letter. “I have done my duty.”

Almost half a million people have signed a petition, started in February, calling for a European ban on glyphosate, regulatory reform and mandatory targets for reducing pesticides use.

If the number of signatories reaches a million, the European commission will have to consider a legislative proposal under its citizen initiative rules.